The orange eyes are a bit obviously demonic (pretty much Linda Blair stuff) instead of a natural progressive deterioration (unless as I suggested earlier you factor in liver damage in which case the poor bugger would be jaundiced as well, though that would make the whole eye yellowy orange).

Emperor Palpatine doesn't seem to give a damn about his looks and if Luke can see better with a blast shield down why would he (the Master of the Dark Side) bother to have surgery on his eyes?

Vader trapped inside his mechanical suit as much as sustained by it but Palpatine is pure natural nastiness.